Gas analyzers are useful machines for measuring the content of gas mixtures, particularly, the gas industry and in industrial uses of various gas mixtures. Previous gas analyzers include those which utilize infrared radiation, chemical cells, and thermal conductivity sensors. The content of a given gas can be computed by comparing its known properties against the readout displayed by the analyzer.
Prior art gas analyzers required frequent calibration and could not be readily adapted to measure varying mixtures of sample and reference gases. Particularly, analyzers which measured content based on thermal conductivity required that the user change the analyzer current, mix a number of known samples to determine the analyzer output at each mixture, calculate the analysis curve and enter the data, and finally to recalibrate the gas range with a known accurate gas sample. This procedure sometimes takes a full working day for an instrument technician to accomplish. Often, the prior machines were returned to the factory for recalibration at the customer's expense.